Thank you for the feedback.
I've been hyper avoiding fullscreen on my last couple of games because of my noobiness.
It makes the UI elements go all wonky with the way I have it set up (because I haven't got used to managing different screen sizes).
I'm gonna make an honest effort to actually fix the UI today so that you can see everything in fullscreen because this is totally disgraceful.
I'm also gonna fix the issue you are having with the escape key.
I don't know how to consume key input; that's an interesting question though.
My solution will be to change which key resets the game to something sensible, like 'n' or 'enter'.